Multioperation-Mode Light-Emitting Field-Effect Transistors Based on van der Waals Heterostructure.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) semiconductors, like transition metal dichalcogenides (TMDs), exhibit strong photoluminescence (PL).
• Efficient electroluminescence (EL) in 2D materials is hindered by poor charge injection and recombination efficiencies.
• Achieving efficient EL is crucial for developing 2D optoelectronic devices.

Purpose of the Study:

• To demonstrate multioperation-mode light-emitting field-effect transistors (LEFETs) using a monolayer WSe2 channel and graphene contacts.
• To achieve efficient and electrically tunable electroluminescence in 2D semiconductor devices.
• To explore the potential of these LEFETs for novel optoelectronic applications.

Main Methods:

• Fabrication of LEFETs with a monolayer WSe2 channel and graphene electrodes.
• Integration of two top gates for selective and balanced charge carrier injection.
• Characterization of electroluminescence and electrical transport properties.

Main Results:

• Demonstration of visibly observable electroluminescence with high external quantum efficiency (≈6%) at room temperature.
• Achieved efficient electron-hole recombination within the confined 2D channel.
• Exhibited multioperation modes (antiambipolar, depletion, unipolar) through electrical tunability.

Conclusions:

• The developed 2D semiconductor LEFETs offer a promising platform for high-efficiency, multifunctional optoelectronics.
• Electrical tunability of channel and contacts enables versatile device operation for transistors and photodetectors.
• These findings highlight the potential for heterointegrated 2D optoelectronic devices.